The present invention relates to polymorphic, amorphous and hydrated forms of the title compound which has the chemical structure shown below: 
The compound is a potent and selective cyclooxygenase-2 (COX-2) inhibitor, useful primarily in the treatment of inflammation, pain and fever as well as other COX-2 mediated diseases, such as described in PCT Publication Nos. WO096/10012 and W096/16934. Compound A is described in U.S. Pat. No. 5,861,419 granted on Jan. 19, 1999 (Example 23) incorporated by reference in its entirety.
Bipyridyl compounds generally are highly crystalline, poorly water soluble and hydrophobic, resulting in difficulties in the preparation of pharmaceutical formulations and problems associated with bioavailability. Accordingly, efforts were made to discover other forms of Compound A and to investigate the properties thereof. There were discovered three additional polymorphic forms, an amorphous form and two hydrates.
Polymorphic forms of Compound A, for purposes of this invention, are identified as Form I (onset of melting, m.p. 134-136xc2x0 C., peak m.p. 138xc2x0 C.), Form II (onset of melting, m.pxcx9c131xc2x0 C., peak m.p. 133xc2x0 C.), Form III (onset of melting, m.p.xcx9c133xc2x0 C., peak m.p. 135xc2x0 C) and Form IV (onset of melting, m.p.xcx9c134xc2x0 C., peak m.p. 136xc2x0 C.). Forms I through IV are anhydrous. An amorphous form and two hydrates have also been identified.